Shades of Darkness – “The Unknown Tear” [Campaign 10, Mission 3]

Hello everyone!

I wanted to ask about the boss in this mission - Kirin. No matter what army I build, at the beginning of the battle, Raileigh has a specific number of each unit. Is this a bug, or is it intentional? Please advise on what tactics to use. :)

Thank you)
*sorry if I messed up with the rules for creating a topic*